Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only say read-only/idempotent/non-destructive; the description adds the non-obvious behavior that only not-yet-started sessions are returned and that output shape is conditional — price per seat class when a movie is given, price of the Standard class otherwise. It also discloses provenance ('cavea.ge'), which matters for an openWorld tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core scope and ordering, then filters, then return fields, then the cross-tool pointer. Every sentence carries information, though the filter enumeration mildly duplicates the schema and the closing provenance sentence is optional.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Thorough for a 7-parameter, zero-required read tool: scope, filtering, ordering, conditional output shape, and next-step integration are all covered, so an agent can call it correctly with no parameters or with any filter subset.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so baseline is 3, but the description adds real meaning beyond the schema: specifying 'movie' changes the price granularity of the response, an effect not visible in the parameter's own description. It also names the upstream tools that supply movie and cinema codes, though that is partly redundant with the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Lists the sessions of the movies of Cavea') plus two sharp constraints that distinguish it from siblings: one date only, and only sessions that have not started. The ordering rule (by start time) further pins down the semantics an agent can rely on.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explains how to narrow the result set (movie, cinema, audio language, format) and gives a downstream workflow pointer ('Use the session code in cinema_get_seat_map'), which tells the agent where this tool sits in a chain. It lacks an explicit exclusion or 'use X instead' statement relative to cinema_list_movies, so it stops short of a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.